Kotlin in Hindi Do while loop

Kotlin do...while Loop

The do...while loop is similar to while loop with one key difference. The body of do...while loop is executed once before the test expression is checked.

Its syntax is:

do {
   // codes inside body of do while loop
} while (testExpression);

How do...while loop works?

The codes inside the body of do construct is executed once (without checking the testExpression). Then, the test expression is checked.

If the test expression is evaluated to true, codes inside the body of the loop are executed, and test expression is evaluated again. This process goes on until the test expression is evaluated to false.

When the test expression is evaluated to falsedo..while loop terminat


Example: Kotlin do...while Loop

The program below calculates the sum of numbers entered by the user until user enters 0

To take input from the user, readline() function is used. Recommended Reading: Kotlin Basic Input

fun main(args: Array<String>) {

    var sum: Int = 0
    var input: String

    do {
        print("Enter an integer: ")
        input = readLine()!!
        sum += input.toInt()

    } while (input != "0")

    println("sum = $sum")
}

When you run the program, the output will be something like:

Enter an integer: 4
Enter an integer: 3
Enter an integer: 2
Enter an integer: -6
Enter an integer: 0
sum = 3